Verizon Wireless will become a little less hospitable for subscribers who want the latest and greatest smartphones. Subscribes will now have to wait a full 24 months for discounted upgrades.

Previously, Verizon offered a discount on a new phone every 20 months. Customers whose contracts expire in January 2014 or later will be the first ones affected by the new 24-month upgrade policy.

“The change allows customers to plan on a single upgrade date for each of their connected devices and is in keeping with how the majority of customers purchase their new phones today,” Verizon said in a statement.

Verizon will also remove the option to transfer upgrades between different types of devices. That means you can't purchase an on-contract tablet at a discount using an upgrade from a smartphone plan, or vice versa. Customers on the same account can still transfer upgrades to one another, as long as they're for the same type of device.

What about other carriers?

Other carriers are more generous with their upgrade policies. AT&T and Sprint allow for one discounted upgrade every 20 months. AT&T also allows customers to upgrade earlier by paying an extra $250.

T-Mobile works a bit differently. Under its new subsidy-free plans, subscribers owe a down payment up front, plus two years of monthly installments until the full price of the phone is paid off. Customers can upgrade any time by paying the balance of what they owe.

While Verizon's looking the worst for early upgrades now, there's no guarantee other carriers won't follow—they often do.